package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo8 {
    public static void main(String[] args) {
        try (Connection connection = DBUtil.getConnection()){
            Statement statement = connection.createStatement();
            String sql = "SELECT COUNT(*) count ,c.name\n" +
                    "FROM class c\n" +
                    "         JOIN student s ON c.id = s.class_id\n" +
                    "GROUP BY c.name;";
            ResultSet rs = statement.executeQuery(sql);
            while (rs.next()){
                int count = rs.getInt("count");
                String cName = rs.getString("c.name");
                System.out.println("人数:"+count+",班级:"+cName);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
